The present invention relates to manufacturing equipment and methods, particularly equipment and procedures which may be involved in the making of optical items, such as polarizing beam splitter (xe2x80x9cPBSxe2x80x9d) prism assemblies, for use in, for example, interferometers and other optical products. More particularly, the present invention relates to blocking technology, i.e., holding or supporting technology, for holding prisms or other optical workpieces or items in a selected position for performing work on them efficiently, with precision, and without inducing strain that could deform them.
Blocking or supporting optical elements is known in the manufacture and treatment of high precision optics and optical items such as prisms, mirrors, lenses, windows and the like. One method of blocking may involve a blocking tool and the use of pitch xe2x80x9cbuttons.xe2x80x9d The buttons comprise deposits of blocking pitch, usually in the form of small discs, which are applied to a surface or surfaces of the optic being blocked or supported. The pitch button size, form factor, location on the optic surface and adherent qualities are variables which may affect the blocking process.
Currently, pitch button blocking is done by hand, using trained experts who apply a selected number of buttons, of a selected size, to a selected location or locations on a workpiece. The process is very time consuming and requires highly trained operators and experts, and thus is currently labor intensive. Even using trained technicians, it typically takes one to two days to xe2x80x9cbuttonxe2x80x9d a set of prisms using the traditional, known methods.
Another problem is that, although experts are used, the consistency of the button size and layout location could be improved. In fact, the button-to-button volume variation using traditional methods is typically greater than 60%.
Clearly, there is need for an automated apparatus and method of dispensing pitch buttons to reduce the labor involved, to reduce the need for xe2x80x9cexpertxe2x80x9d technicians, to shorten the pitch buttoning cycle time and to increase the consistency and repeatability of the pitch button size and layout location.
The present invention provides an apparatus or system and method for dispensing or applying a selected amount of supporting or holding material to a selected location on a workpiece.
In one embodiment, the present invention provides a work station and method for applying a blocking material, such as pitch or the like, to a selected location on a workpiece, wherein the work station includes an automated blocking material dispenser, a positioning stage for positioning the workpiece and a microprocessor, and wherein the method includes the synchronized and complimentary operation of the positioning stage and the dispenser under control of the microprocessor to deposit a selected amount and shape of the blocking material in a selected location or locations on a workpiece or workpieces with a high degree of repeatability in a short cycle time.
In another embodiment, the present invention provides a work station comprising an automated pitch dispenser for dispensing or applying one or more pitch buttons to a workpiece or workpieces, and a positioning stage for positioning the workpiece(s), wherein the dispenser and positioning stage are coordinately operated and controlled by a suitable computer or microprocessor and software. The work station may include appropriate peripheral devices and apparatus such as a preheating oven, sensing or process monitoring devices, and workpiece carriers and/or tool holders.
In one embodiment, the method of use or operation of the pitch button station of the present invention comprises the positioning stage, for example an X-Y stage, moving or positioning a workpiece or workpieces, such as pre-heated optics, relative to a pitch dispenser, and the dispenser depositing pitch buttons on the positioned workpiece(s). In this embodiment, wherein the pitch dispenser and the X-Y stage are controlled by a computer and appropriate software or program(s), the buttons are positioned at precise, selected positions, in a precise selected size, in a very short cycle time, and with a high degree of repeatability.
An advantage of the present invention is that it speeds the xe2x80x9cbuttoningxe2x80x9d process from the typical one to two days to button a set of prisms using known methods to about an hour.
Another advantage of the present invention is that button volume variants are expected to decrease to less than 8%. This is advantageous because it creates greater process consistency, resulting in reduced polishing time and better flatness control of the optics.
Advantageously, the pitch button apparatus and method of the present invention will help reduce manufacturing costs and new product introduction costs by using a continuous process. It will further the goal of developing manufacturing processes which enable fast response to market needs. It will facilitate the development of high and consistent yields of optics, reduce process variability, and provide for the easier, more accurate monitoring and accumulation of cost and quality information and management.
Additional advantages of automating pitch button blocking in accordance with the present invention include shortening lead time, removing the need for as many experts in the buttoning process, allowing achievement of better flatness control, increasing yields through greater blocking process consistency and supporting production goals, particularly as regards certain optics, such as 1 inch, 2 inchxc3x971 inch, and 4 inchxc3x971 inch prisms, from a common blank and fabrication process. In particular, the apparatus and method of the present invention saves money and provides for increased production levels.
In one embodiment, the pitch button dispensing station of the present invention is a customized work station which automatically deposits pitch buttons on prisms.
The pitch button dispensing station system or assembly of the present invention may be incorporated conveniently into current manufacturing lines and/or facilities, and it may be adapted or configured to improve and/or conform to a particular material flow.